Field emission devices (FEDs) are known in the art and may be realized using a variety of methods some of which require complex materials deposition techniques and others which require undesirable etch steps.
Typically FEDs are comprised of an electron emitter electrode, a gate extraction electrode, and an anode electrode although two element structures comprised of only an electron emitter electrode and anode are known. In a customary application of an FED an appropriate externally provided potential is applied to the gate extraction electrode so as to induce an electric field of suitable magnitude and polarity such that electrons may tunnel through a reduced surface potential barrier of finite extent with increased probability. Emitted electrons, those which have escaped the surface of the electron-emitter electrode into free-space, are generally preferentially collected at the device anode. In a two element structure the gate extraction electrode will serve also as the anode for the purpose of collecting emitted electrons.
Various device geometries which may be realized using the known methods include FEDs which emit electrons substantially perpendicularly with respect to a supporting substrate. One such geometry employs a conic shaped electron emitter disposed on a substrate or conductive surface and having an apex which forms a geometric discontinuity of small radius of curvature at which apex electrons are preferentially emitted. Techniques for forming such electron emitters, known in the art, are restricted with respect to the shapes and sizes of electron emitter structures which may be realized.
Accordingly, there is a need for a field emission device and/or a method for forming a field emission device which overcomes at least some of the shortcomings of the prior art.